1. Field of the Invention
This invention relates to a process for treating fiberfill fibers with aqueous dispersions of organopolysiloxanes.
2. Background Art
Emulsions of crosslinked silicones are known. Catalysts comprising (heavy) metals or free of metals are required for crosslinking silicones in addition to crosslinkers. In some cases, inhibitors are also used to control reactivity and pot life in order that any unwanted, premature gelling may be prevented.
Metal-free aqueous RTV1 dispersions are described in EP 828 794 A and EP 655 475 A1. They are obtainable using the three starting components:
(A) organopolysiloxanes comprising condensation-capable groups,
(B) (amine-free) organosilicon compounds acting as crosslinkers in that they have at least 3 crosslinking-reactive groups,
(C) organosilicon compounds comprising basic nitrogen, more preferably the alkali metal siliconates of the compound, which are catalytically active.
Component (C) confers a very high pH of the products, which presents difficulties in processing.
DE 102004038148 A1 (equivalent to WO 2006/015740 A1) describes the preparation of high-viscosity silicones (10,000 to 50,000,000 mPa·s) in emulsion by reaction of silanol-terminated organopolysiloxanes with α-aminomethylalkoxysilanes. However, no elastomeric silicone films insoluble in toluene are obtained.
EP 510 631 A describes the preparation and the finishing with a fiber-finishing agent based on copolyesters grafted with polyorganosiloxanes, for a soft featherlike hand for polyester fiberfill fibers. The lateral grafting of polyorganosiloxanes onto the polyester backbone gives a finishing agent which produces a smooth, low-friction hand on fibers, in particular polyester fiberfill fibers.
GB 1458319A (equivalent to DE 24 20 151 A) describes novel manufactured fibers and a process for their production wherein a reactive polysiloxane is used in combination with aminoalkoxysilane and a curing agent, a metal salt of 2- to 4-valent metal ions, such as dibutyltin diacetate or zinc acetate, under heat treatment of 120 to 200° C.
DE 35 03 457 A discloses a process for impregnating organic fibers wherein an organopolysiloxane having amino groups, such as aminoethylaminopropyl groups, is crosslinked with hydrosiloxane in the presence of metal-containing catalysts, such as dibutyltin dilaurate.
EP 1 096 059 A describes an aqueous emulsion for treating polyester fibers which contains a mixture of an emulsion of an amino-functional organopolysiloxane having alkoxy groups and an emulsion of an amino-functional organopolysiloxane having hydroxyl groups. The two organopolysiloxanes first have to be prepared by reaction of α,ω-dihydroxydimethylpolysiloxanes with N-(2-aminoethyl)(3-aminopropyl)methyldimethoxysilane or by reaction of α,ω-dihydroxydimethylpolysiloxanes or cyclic dimethylpolysiloxanes with the hydrolysis or condensation product of N-(2-aminoethyl)(3-aminopropyl)methyldimethoxysilane, respectively. High molecular weight linear polysiloxanes are obtained, but not crosslinked films insoluble in toluene.